Safety device for die presses



Aug. 14, 1934. H. c. H. WALSH SAFETY DEVICE FOR DIE PRESSES Filed Feb. 7. 1934 2 Sheets-Sheet l H. C. H. WALSH SAFETY DEVICE FOR DIE PEESSES Aug. 14, 1934.

Filed Feb. '7. 1934 2 Sheets-Sheet 2 4 3 y 4 A III w W w, 2 JW M a Q96 3 m 8 7 5 I 2 a I J m; a fly 1% 4 M w? r a w Kw 7 w 5 3 IN 6 m? My II/IIIIIIIIIIIIII 1 Patented Aug. 14, 1934 U-Nirsp srA'res PATENT orriee SAFETY DEVICE FOR DIE PRESSES Harry G. H. Walsh, Chicago, 111. Application February 7, 1934, Serial No. 710,081

Claims.

The attachments constituting the subject matter of the present invention are designed as an improvement upon the mechanisms shown and described in Patent No. 1,047,349, issued Decemmeans of a foot treadle'which actuates the clutch mechanism for engaging the crank shaft of the die press with the constantly rotating fly wheel, and in suchcircumstances, unless adequate safety appliances are provided, the hands of the operator will remain free during the descent of the die stamp or similar mechanism, with the result that accidents quite frequentlyoccur.

The present invention'is-designed to require the conjoint operation of thehandsas well as the foot of the operator inorder to'effectively'engage the operating parts, so that it will be impossible for the operator toactuate the mechanism: and leave his hands free while the die stamp is de-- scending.

The mechanism; described and claimedin the prior patent above referred to isdesigned fora similar purpose, but the present invention constitutes a distinct improvement thereon inthe simplification of the operating parts and the-provision of a morecompact and readily applied.

safety device than thatdisclosed inthepatent referred to. In particulanthe present invention is directed to the provision. of a pair of push,

buttons which the operator is required to depress in order to permit of a clutching engagement of theoperating parts. of. both push buttons, save under special circumstances, the foot treadle remains locked, and in order to effectively actuate the clutch, it is necessary not only to depress the push buttons but Prior to the depression.

Fig. 2 is a plan view of the bed of the press, with the safety appliance arranged in front thereof; p e V r Fig. 31s a detail of certain portions ofthe foot treadle connectionstaken on line 3-3 of Fig. 1;

Fig. 4 is a sectional elevation taken on line l40fFig.2; v V Figs. 5 and 6 are similar views showing the parts in different operating positions;

Figs. '7, 8 and 9 are sectional elevations taken respectively on lines 7, 8 and 9 of Figs. 4, 5 and 6, showing the latching mechanism in various positions of adjustment;

Figs 10 is a similar view showing still another position of adjustment; and

Fig. 11 is a sectional detail takenv on line 1-1 of Fig. 2. V l

The die press. of the.present invention. comprises a main frame ofthe usual configuration, which supports a bed' plate 21v abovev which the frame extends to the. usual elevationltoafford a bearing for a crank 'shaft22" on which'i's mounted the usual fly wheel. Clutchmechanism- 24' of the conventionaltype is provided for clutching, the parts together by the down swingingof a lever .25v pivoted at 26 and adapted to be actuated through a train of connections, which in eludes an upper link rod 27; a lowerlink rod 28, and bell'crank mechanism 29 which will'be here after described more in detail; The lower link" rod 28 connects with the shank of a foot treadle 30 pivoted atsl and projecting forwardly into convenient operating position near the front base portion of the machine; The crankshaft 22 operates the usual plunger 32, which. need not be described in detail.

The above mechanisms, with, the exceptionof the connections 29, areof the conventionalcharacter, so that further description, thereof is deemed unnecessary.

- The. safety appliances more particularly forming the subject of the present invention-comprise a casting 33 whichis cored to afford an elongated. chamber 34 deepened in-the center to provide'a shallow well 35. The top wall 36 of-the casting lies in flush relation to the surface of the bed plate 21. 'Within the chamber 34 is locatedan' elongatedequalizer bar 37, which is upturned at each end to provide a push button 38 operating through a throated aperture 39. The equalizer bar'iirits'center is providedwith a depending lug, 40 which is pivoted at 41 to the horizontal arm 42.0fja bel1 .crank'1ever 43, thevertic'al arm i iof' which is connected with a draw rod 45' extending outwardly through the end of the elongated chamber.

The rod 45 terminates in a dog 46 slidably mounted within the inwardly projecting arm 4'7 of 5 a housing 48, which is secured to the bed plate near the forward edge thereof. The dog 46 terminates in a beveled tooth 49 which when projected bears against a shoulder 50 formed in the side face of a ratchet bar 51, and immediately below the shoulder, the edge of the ratchet bar is serrated by the provision of rearwardly projecting teeth 52. The arrangement is such that when the dog is outwardly projected to bear against the shoulder 50, as in Figs. 7 and .8, the ratchet bar will be locked in position to prevent the operation of the foot treadle, and likewise, when the tooth of the dog engages any one of the teeth or serrations of the ratchet bar, further movement of the bar will be prevented, so that in order to permit equalizer bar, so that, in order to operate the draw rod 45, as in Fig. 6 it is necessary for the operator of the machine to press down both of the push buttons, thereby requiring employment of both hands, so that the possibility of placing one or both hands within the range of movement of .the operating parts of the die press or punch is prevented. g s V In some circumstances, however it is necessary to permit the operator to use one of his hands'in the manipulation of large sheets orthe like in .,,the pressing operations, and under these circum- 40 stances the parts may be adjusted to permit the required degree of movement to 'be'imparted to; the bell crank 43 by the depression of one only of the push buttons 38. Figs. 2 and llillustrate the means provided to permit of this adjustment.

At each end of the casting 33 is located a set screw 56, which is threaded through the front wall of the casting and provided with a head 57 having a transverse aperture58 through which extends a locking rod 59 providedat one end with a loop 60 adapted to receive a padlock 61 which is passed through an aperture in a lug 62, so that the set screws 56 can be locked against rotation.

As shown in Fig. 11, when either one of the set screws is adjusted inwardly, its inner reduced end 63 is brought into engagement with a recess 64 in the equalizer bar at or near the end thereof, so that, with the set screws thus adjusted, the inner end 63 furnishes a pivot or fulcrum for the equalizer bar, which then normally occupies the tilted position shown in Fig.5, with one of the push buttons depressed to the limit and the other push button elevated abnormally, which thus affords a 'suiilcient range ofmovement to permit .the equalizer bar to act as a lever in imparting the required degree of movement to the bell crank 43. The ratchet-bar .51 connects with a link 65, the outer end of which is pivoted to the lower end of a. swinging arm 66 pivoted at its upper end on a -pivot67, and connected by means of a link 68 with "a bell crank leverarm 69, the companion arm '70 of which connects with the treadle draw rod 28, the arrangement being such that when the ratchet bar 5 1'is locked by the dog 46, it will be impossible 'or theparts actuated thereby.

,tofimpart any downwardmovement tothe treadle The bell crank arms 69 and '70 are formed on a sleeve 71, which is journalled upon a pintle 72 outstanding from the main frame of the machine, and said pintle also forms a journal mounting for a second bell crank comprising a sleeve '73 having a laterally extending arm 74 and an upwardly extending arm 75 projecting therefrom. The arm 74 connects with the draw rod 27, and the arm '75 is provided at its upper end with an overhanging head '76 through which is entered a contact pin 77 beveled at its lower end and engaged by a rocking pin '78 carried by an ear 79.

The arrangement of these parts is such that when the treadle is free to act, a depression of the treadle will impart a downward swinging movement .to the arm 70 and an inner thrust to the pin 78, which in turn will impart a forward swinging movement to the bell crank arm '75 with a corresponding down swinging of the arm '74, which draws down the link 2'7 and the lever 95 25, thus setting the clutch pin and starting the operation of the main crank shaft 22.

The depression of the foot treadle throws the various connections into the respective positions indicated by dotted lines in Fig. 1, but it will be understood that the present invention is not primarily concerned with any particular form in the train of operating connections in so long as the same include a member which is connected with the ratchet bar 51, so that the entire train of connections will be locked by the locking of theratchet bar.

The operation of the device will in the main be understood from the foregoing description, but may bebriefiy outlined as follows: Under ordinary conditions, where it is desired to engage both of the hands of the operator during the descent of the die stamp or other corresponding mechanism, both set screws 56 are retracted out of engagement with' the equalizer bar, so that the latter must be depressed at both ends at the same time in order to impart a draw to the rod 45 and to-effect a retraction of the dog to the extent necessary to release the ratchet bar 51. It is also important to require a continuance of the depression on the push buttons during the entireclepression of the foot treadle, and the ratchet teeth'52 are provided to insure such continued depression, since otherwise the operator might, by mere momentary depression of the equalizer bar, release the dog, and immediately thereafterand before clutching engagement, employ his hands in an unauthorized manner which might result in injury. By the arrangement shown, it is necessary to maintain the parts in unlocked relation until the clutch is fully engaged and the operation begins. Where it is necessary,.however, to permit to the operator the use of one of his hands, the parts may be adjusted as in Fig. 5, which transforms the equalizer bar into a lever andafiords a sufficient range of movement at the free end of the bar to perform the operations previously described.

The device is simple and compact in form and is to a large extent self-contained, so that it may be readilyapplied to existing machines with but slight re-arrangement of the treadle controlled train of connections to include a link or similar member which connects with the ratchet bar.

, Although the invention has been described with particularity as to detail, it is not the intention to limit the invention strictly to the form shown, since modifications in detail may be introduced without departing from the spirit of the invention.

I claim:

anisrn and connections for actuating the clutch, and safety mechanisms including a slidably mounted ratchet bar movable with said clutch" connections, said ratchet bar having a deep notch and anadjacent series of relatively shallow ratchet teeth, a dognormally engaged-with saidnotch',

and handcontrolled members adapted when actuatedto retract saiddog to permit the foot treadle and clutch mechanisms tobeoperated.

2'. Incombination' with clutch actuated mechanisms of the class described,- foot tread1e'mechanism and connections for actuating the clutch, and safety mechanisms including a slidably mounted ratchet bar movable with said clutch.

connections, saidjratchet bar having adeep notch and an adjacent series of relatively shallow ratchet teeth,- a dog normally engaged with said notch,

and an equalizer bar provided at eachend with a push button, and connections-between the dog and the medial portion of" the equalizer barfor retracting the dog upon depressionof the medial portion of the equalizer bar when movedthrough a predetermined range.

3. In combination withclutch actuated mechanisms of the class described, foot treadle mechanism and connections for actuatingthe clutch, and safety mechanisms including a slidably mounted ratchet bar movable with said clutch connections, saidra'tchet' bar having a deep notch and an adjacent series of relatively shallow ratchet teeth, a' dog normally engaged with said a predetermined range, and means for pivoting one end of the equalizer bar in depressed position to permit effective actionof'the-bar by depression of the free end thereof;

4. In combination with clutch actuated mechanisms of the class described, foot treadlemech anism and connections for actuating the clutch,

and safety mechanisms including a. slidably mounted ratchet bar movable-with saidclutch connections, said ratchet bar h'avinga deep notch and an adjacent series of relatively shallow ratch et teeth,- a dog normally engagedwith' said notch; and an equalizer bar provided at each end with a push button, connections between the dog andthe medialportion of the equalizer-bar for r'e-'- tracting the dog upondepression of the medial portion of the equalizer bar when movedthrough' a predetermined range; and a-set screw a'daptedto be adjustedtoengage and pivot one end of thebar in depressed position to permit efiective operation of the equalizer barby depression oithe free end thereof.

5. In combinationwith clutch actuatedmechanismsof the class described,- foot treadle mechanism and connection for actuating the-clutch," and-safety mechanisms including a slidably mounted ratchet bar movable with said clutch connections, said ratchet bar having a deep notch and an adjacent series of relatively shallow ratchet teeth, a dog normally engaged with said notch,

and an equalizer bar provided at each end with a push button, connections between the dog and the medial portion of the equalizer bar for retracting the dog upon depression of the medial portion of the equalizer bar when moved through a predetermined range, and a set screw adapted 1 P r to be adjustedlto engage and pivot'one en'dof. the l. Incombination with clutch actuated mechanisms of the class described, foot treadle mech barinidepressed position to permit effective operation ofthe equalizer bar by depression of the free endthereOf', and means for locking saidset screw'in bar engaging position.

6. In combination with clutch actuated mechanisms of the class described, including a. foot treadle and connections for. actuating the clutch, said connections including a bell'crank, a slidably mounted ratchet bar connected and movable with'said bell'crank, said ratchet bar being provided on its inner edge witha notch, av dog mounted for slidable movement in aline transverse to the line of movement of the ratchet bar and normally engagingthe notch in said ratchet bar and adapted upon retraction to release said ratchetbar; and hand actuatedsafety mechanism adaptedqwhen operated to retract said dog to unlock the foot treadle and'clutch actuating mechanism.

'7; In combination with clutchactuated mechanisms of the class described, including afoot treadle and'connections for actuating the clutch, said connections including a bell crank, a slidably mountedratchet bar connectedand movable with said bell. crank, said ratchet bar being'prov-ided on its inner edge with a notch and a series-of relatively shallowratchet teeth in adjacent relation erated to retract said dog to unlock the foot treadlc and. clutch actuatingconnections.

8; In combination with clutch actuated mechanisms. oihth'e class described, including a foot treadle'and connections for actuating the clutch,

said conn'ectionsincluding a bell crank,"a slidably 1,

mounted ratchet bar connectedand movable with said bell crank, said'ratchet' barbeing provided on its inner edge with a-notch,' a dog mounted for slidable movement in a line transverse to the line of movement of the ratchet'bar and normally engaging the notch in' said ratchet bar'and adapted upon'retraction' to release said ratchet bar, an equalizer barprovidedat each end witha push botton, and connections between the'dog and the medial portion of-the equalizer bar for retracting the dog upon depression of the-medialportion of theequalizerbar when moved through a predetermined. range. a

*9. :In' combination with clutch actuated mechanismsnof. the classdescribed, including afoot treadle and connections for actuating'the clutch,

saidconnections includingv a bell crank, a slidably mounted ratchet-bar'connectedand movable with said-bell. crank; said ratchet bar being provided on its inner edge with a notch, a dog mountedfor slidable movement in a linetransverse to the line of movement of the ratchet bar and'normally engagingthe notch-in said ratchet bar and adapted upon retraction to release said ratchet bar, an equalizer bar providedat eachend with a push button, and connections between the dog and the medial portion of the equalizer bar for retracting the dog upon depression of the medial portion of the equalizer bar when moved through a predetermined range, and means for pivoting one end of the equalizer bar in depressed position to permit eliective action of the bar by depression of the free end thereof.

10. In combination with clutch actuated mechanisms of the class described, including a foot treadle and connections for actuating the clutch,

said connections including a bell crank, a slidably.

mounted ratchet bar connected and movable with said bell crank, said ratchet bar being provided on its inner edge with a notch, a dog mounted for slidable movement in a line transverse to the lineoi movement of the ratchet bar and normally engaging the notch in said ratchet bar and adapted upon retraction to release said ratchet bar, an equalizer bar provided at each end with a push button, and connections between the dog and the medial portion of the equalizer bar for retracting the dog upon depression of the medial portion of the equalizer bar when moved through a predetermined range, and. a set screw adapted to be adjusted to engage and pivot one end of the equalizer bar in depressed positionto permit effective operation of the bar by depression of the free end thereof.

11. In combination with clutch actuated mechanisms of the class described, including a foot treadle and connections for actuating the clutch, said connections including :a bell crank, a slidably mounted ratchet bar connected and movable with said bell crank, said ratchet bar being provided-on its inner edge with a notch, a dog mounted for slidable movement in a line transverse to the line of movement of the ratchet bar and normally engaging the notch in said ratchet bar and adapted upon retraction to release said ratchet bar, an equalizer bar provided at each end with a push button, and connections between the dogand the medial portion of the equalizer bar for retracting the dog upon depression of the medial portion of the equalizer bar when moved through a predetermined range, a set screw adapted to be adjusted to engage and pivot one end of the equalizer bar in depressed position to permit effective operation of the bar by depression of the free end thereof, and meansfor locking said set screw in bar engaging position.

12; In combination with clutch actuated mechanisms of the class described, including a foot treadle and connections for actuating the clutch, said connections including ,a bell crank, a slidably mounted ratchet bar connected and .movable with said bell crank, said ratchet bar being provided on its inner edge with a notch and a series of relatively shallow ratchet teeth in adjacent relation to the notch, a dog mounted for slidable movement in a line transverse to the line of movement of the ratchet bar and normally engaging the notch in said ratchet bar and adapted upon retraction to release said ratchet bar, an equalizer bar provided at each end with a push button, and connections between the dog and the medial portion of the equalizer bar for retracting the dog upon depression of the medial portion of the equalizer bar when moved through a predetermined range.

13. In combination with clutch actuated mechanisms of the class described, including a foot treadle and connections for actuating the clutch, said connections including a bell crank, a slidably mounted ratchet bar connected and movable with said bell crank, said ratchet bar being provided on its inner edge with a notch and a series of relatively shallow ratchet teeth in adjacent relation to the notch, a dog mounted for slidable movement in a line transverse to the line of movement of the ratchet bar and normally engaging the notch in said ratchet bar and adapted upon retraction to release said ratchet bar, an equalizer bar provided at each end with a push button, and connections between the dog and the medial portion of the equalizer bar for retracting the dog upon depression of the medial portion of the equalizer bar when moved through a predetermined range, and means for pivoting one end of the equalizer bar in depressed position to permit effective action of the bar by depression of the free end thereof.

14. In combination with clutch actuated mechanisms of the class described, including a foot treadle and connections for actuating the clutch, said connections including a bell crank, a slidably mounted ratchet bar connected and movable with said bell crank, said ratchet bar being provided on its inner edge with a notch and a series of relatively shallow ratchet teeth in adjacent relation to the notch, a dog mounted for slidable movement in a line transverse to the line of movement of the ratchet bar and normally engaging the notch in said ratchet bar and adapted upon retraction to release said ratchet bar, an equalizer bar provided at each end with a push button, and connections between the dog and the medial portion of the equalizer bar for retracting the dog upon depression of the medial portion of the equalizer bar when moved through a predetermined range, and a set screw adapted to be adjusted to engage and pivot one end of the equalizer bar in depressed position to permit effective operation of the bar by depression of the free end thereof.

15. In combination with clutch actuated mechanisms of the class described, including a foot treadle and connections for actuating the clutch, said connections including a bell crank, a slidably mounted ratchet bar connected and movable with said bell crank, said ratchet bar being provided on its inner edge with a notch and a series of relatively shallow ratchet teeth in adjacent relation to the notch, a dog mounted for slidable movement in a line transverse to the line of movement of the ratchet bar and normally engaging the notch in said ratchet bar and adapted upon retraction to release said ratchet bar, an equalizer bar provided at each end with a push button, and connections between the dog and the medial portion of the equalizer bar for retracting the dog upon depression of the medial portion of the equalizer bar when moved through 

